Abstract
In pursuit of sustainable resource utilization on the Moon, this paper delves into modeling and characterization of particle size distribution (PSD) of lunar regolith simulants in an electrostatic system. A prototype electrostatic sieve was built and tested with four sample simulants mirroring properties of lunar mare and highland regolith. An alternating four-phase (90 degrees, 180 degrees, 270 degrees, 360 degrees) traveling square-wave was utilized for particle-directed transport to model the diverse trajectories of the particles. Numerically, we scrutinized how the distribution functions of the particles are manifested as the electrostatic field propagates, with a focus on three distinct particle ranges (<105, 105-250, 250-500 mu m) of four simulants. Results indicated considerable influence of sorting mechanism and control parameters on electrostatic sieve's operation. These parameters encompass column inclination angles (10 degrees, 15 degrees, 20 degrees) and port length (from inlet 10 to 50 cm) at different excitation frequencies (10, 15, 20 Hz) of power source. We optimized parameters in fitting experimental data and successfully identified the movement of particles under electrostatic field at an average feed rate of 0.18 kg/h (0.05 g/s); however, the existing circular system was ineffective and unable to facilitate sorting and separation of the lunar simulant particles. Overall, the results indicate that while our electrostatic sieve instruments are efficient in moving the regolith simulant particles, its design and operation should be further modified for simultaneous transportation and separation of the particles.